Centrifugal fan



' A. H. CANDEE.

CENT RIFUGAL FAN. APPLICATION FILED on. 21; ms.

Patented May 17, 1921.

Andrew h (a/Mae ATi'ORNEY UNITED STATES PATENT OFFICE.

ANDREW n. CANDEE, or PITTSBURGH, rnNNsYLvANIA, ASSIGNOETO WESTINGHOUSE nnnc'mrc & MANUFACTURING COMPANY, A CORPORATION or PENNSYLVANIA.

Y cEN'rrurUoen FAN.

Patented May 1"), 1921.

Application filed October 21, 1916. Seriallflo. 126,892.

' gal Fans, of which the following is a specication.

My invention relates to centrifugal fans and particularly to fans or pumps in which the fluid to be moved is taken in longitudinally, with respect to the axis of rotation,

and is discharged circumferentially.

.In my copending application, Serial No. 96,058, filed May 8, 1916, is shown and described a centrifugal fan in which bracing end members are disposed obliquely between the lates of the fan in order to prevent relative angular movement of the plates during the. operation of the fan. In order to.

provide a perfectly rigid structure, it is desirable to place the bracing members in a state of tension but, as the respective axes of the bracing members are at an an 1e to the fan plates, it has heretofore been ound diflicult to so secure the bracing members to the plates that they will not tear out when the bracing members are in tension.

The object of my invention is to provide a novel means of securing the bracin members to one or both of the plates so t at the tension of the bracing members will be transmitted to a plane that is substantially normal to the respective axes of the bracing members.

A further object of m invention is to rovide means whereby t e tension of the racing members may be readily ad'usted.

In the accompanying drawings, igure 1 is a perspective view of a centrifugal fan embodying my invention; Fig. 2 is a view,.

similar to Fig. 1, showing a modification of my invention; Fig. 3 is an enlarged fragmentar I of the racing members (shown in Fig. 1) to the fan plates, and Figs. 4 and 5 are. detail views of one of the members shown in view showmg the relation of one.

5 that. are circumferentially arranged in spaced relation between the plates and extend at right angles thereto- The fan, as a whole, is adapted to be mounted on the shaft of a suitable motor (not shown) and the rotation of the blades 5, during the operation of the motor, draws air into the fan in a longitudinal direction, with respect to the axis of rotation, and discharges it tangentially. It has been found, however, that, during acceleration or deceleration of the fan, the ring 4 and the portions of the blades 5 adjacent thereto tend to lag behind or advance ahead of the rin 3 which is connected rigidly to the driving shaft, owing to the inertia of these parts. Consequently, when the direction of rotation of the driving shaft changes, the forces due to the gyroscopic action and inertia tend to cause relative movement of the rings 3 and 4. In order to remedy this undesirable 'efi'ect, bracing members 6 are secured between the plates, with their respective longitudinal axes extending at an angle thereto.

The bracing members 6 are oppositely inclined with respect to each other, and the adjacent ends of each pair are secured to the arms 7 of the Y-shaped plate 8 that is seare punched out at points substantially half way between the supporting plates 8, leaving wedge-shaped tongues 9 within the openings 10 formed by the punch. The tongues 9 are bent upwardl and their respective endportions 9 are bent over into a plane substantiall parallel to that of the plate 3. Feet ll bri ge the openings 10 and, as best shown in Fig. 4, respectively comprise base portions. 12 and a bridge portion 13 that is substantiall parallel to the portions 12 and is connecte thereto by oppositely disposed inclined portions 14. The base ortions 12 are secured to the opposite si es of each opening 10, the intermediate portion 13, be-

ing in engagement with the portion 9 of the plate 3, which partially closes the opening 10, thus aidin in reducing undesirable air currents theret rou h. The portions 14 of each foot 11 then he in planes that are substantially normal to the axes of adjacent bracing members and are respectively provided with openings 15 through which the threaded end' ortions 16 of the bracing members extendias best shown in the right hand portion of Fig. 3. Nuts 17 and 18 are arranged on posite sides of the feet 11 to coact with t e threaded portions 16 and the portions 14 to place the bracing members 6 in a state of tension. The tension may be adjusted to any desired degree and mainranged between said plates,

tained by reason of the locking action between the nuts 17 and 18. The opening 10 provides easy access to the nut 18 and also provides a means of taking care of the end portion 16 which may extend through the plate 3. v

A modification of my invention is shown in Fig. 2 wherein the plate 3 is pressed at properly spaced points to provide portions 19 that project above the surface of the plate 3 and present plane surfaces 20 that are substantially normal to the longitudinal axes of the bracing members 6. The tension of the bracing members may be adjusted in %he manner described with reference to rom the foregoing, it is obvious that, as the tension of the bracing members is transmitted to portions that are substantially normal thereto, a maximum'degree of rigidity is secured, andthe tendency for the bracing members to tear loose from the plate 3 is substantially eliminated. I

While I have shown my invention as applied to a particular type of fanstructure,

1t is not so limited but is susceptible of various modifications within the scope of the appended claims.

I claim as my invention:

1. A centrifugal fan comprising spaced annular plates, a plurality of blades arbracing members extending obliquely from adjacentpairs of said members being disposed in planes substantially parallel to the axis of said plates, one of said plates being provided with portions integral therewith that are substantially normal to the longi tudinal axes of said bracing members through which the said members extend, and means coacting with said portions for placing said bracing means in tension.

annular plates,

2. A centrifugal fan comprising spaced a plurality of blades arranged between said lates, bracing members extending obliquel from plate to plate, each of said bracing members being located in a plane that is substantially perpendicular to said plates and defined by chords less than the diameter thereof, and-means plate to plate,

ing member.

4. A centrifugal fan comprising spaced annular plates, a plurality of blades arranged between said plates, and two sets of oppositely disposed bracing members alternately arranged and extending between said plates, each of said members being disposed in a plane that is parallel to and offset with respect to the axis of rotation of said plates.

5. A centrifugal fan comprising two spaced annular lates, a plurality .of fan blades arranged between said plates, a plurality of bracing members extending obliquely from plate to plate, adjacent pairs of said members located in planes perpendicular to said plates, and means mounted on each of said plates for securing said bracing members thereto.

6. A centrifugal fan comprising two spaced annular lates,. a plurality of fan blades arranged between said plates, a plurality of bracing members mounted in pairs and extending obliquel from plate to plate,

the members of each 0 said pairs being disposed at an angle to each other.

7. A centrifugal fan comprising two spaced annular plates, a plurality of fan spaced annular plates, a plurality of fan blades arranged etween said plates, a plurality of bracin members mounted in' pairs and extending oiliquel from plate to plate, the members of each of said pairs extending in opposite directions, and means mounted on each of said plates for securing said brac-- ing members thereto. j

In testimony whereof I have hereunto subscribed my name this 17th day of Oct.,

ANDREW H. CANDEE. 

